FIG. 50 is a perspective view showing a configuration of a conventional track ball device. A ball 151, an operating element, is held in a main body (not shown) so as to be rotated freely in all directions when having a surface touched by a hand or finger of an operator. On the outer circumference of the ball, rollers 152 and 153 contacts in orthogonal directions from a top view. Rotary encoders 154 and 155 of two-signal type capable of distinguishing the direction of the rotation are coupled to the rollers 152 and 153 as means for detecting the direction and amount of rotation.
When the ball 151 is rotated by the hand or finger, the rollers 152 and 153 rotate, and the rotary encoders 154 and 155 detect the direction and amount of rotation in an X-axis direction and Y-axis direction of the ball 151, and issue signals corresponding to them. A circuit of an electronic apparatus employing this track ball device processes the signals and have a cursor (not shown) on a display screen move in an X-axis direction and Y-axis direction according to the detected direction and amount of rotation.
Recently, as the display screen is having a higher resolution, an electronic apparatus having the display screen increases, and is diversified, and the track ball device has used in a small and portable information terminal. In such electronic apparatuses including the conventional track ball devices, since the ball 151 rotates too freely, the cursor often moves ahead of a desired position or is not held stably at the desired position, and the ball is hardly manipulated finely. Therefore, the track ball device capable of manipulating finely at high precision is demanded. And the track ball device having a switch for issuing a signal indicating that a position of the cursor on the display screen is recognized.
As one of the examples to meet such demand, the track ball device disclosed in Japanese Laid-open Patent No. 8-185259 is known This track ball device, as shown in FIG. 51, has rotary blades 164, 165 and stoppers 166, 167 mounted on rollers 162, 163, give a click feel to an operator manipulating the ball 161.
This track ball device, for generating the click feel, has a rotary torque of the rollers 162, 163 increase because of a hooking engagement of the rotary blades 164, 165 and the stoppers 166, 167. A larger rotary torque is accordingly transmitted at an area where the ball 161 and the rollers 162 contacts, 163, i.e., a portion for transmitting a rotation of the ball 161 to the rollers 162, 163 As a result, the ball is likely to slip on the friction surface of this contacting area, and a clear click feel may not be generated.
Besides, due to a clearance between the rotary blades 164, 165 and the stoppers 166, 167, the ball 161 has a large rotary play angle between the rollers 162 and 163, and jerkiness which may be felt during manipulation.
Furthermore, this device, since being composed of many constituent members, has a size reduced hardly and has a cost lowered hardly.